TOOL FOR SHAPING HOLLOW AXIALLY SYMMETRICAL ARTICLES Russian patent published in 1997 - IPC

FIELD: plastic metal working, namely cold forming with use of elastic medium pressure, particularly production of superthin-wall members of pipeline system. SUBSTANCE: tool is placed in tubular blank 9 in such a way that necked parts 8 of metallic sleeves 6 of end portions 5 of tool are arranged on transition portions of blank joined to its part to be expanded; central portion 7 of elastic cylindrical part 4 is arranged on portion of blank to be maximally expanded, and then said blank is placed in impression of die of forming apparatus. Inner pressure of elastic medium is created at axially upsetting blank. Said pressure is distributed differentially along inner surface of blank depending upon expanding degree. EFFECT: possibility of making superthin-wall complex-structure articles with lowered number of rejects. 1 dwg